Fix infinite loop causing iterator to go out of bounds.

BUG=430252

Review URL: https://codereview.chromium.org/703703004

Cr-Commit-Position: refs/heads/master@{#302748}

ash/virtual_keyboard_controller.cc

@@ -72,13 +72,11 @@ void VirtualKeyboardController::UpdateDevices() {
   // Checks for keyboards.
   has_external_keyboard_ = false;
   has_internal_keyboard_ = false;
-  std::vector<ui::KeyboardDevice> keyboards =
-      device_data_manager->keyboard_devices();
-  for (auto iter = keyboards.begin();
-       iter != keyboards.end() ||
-           (has_internal_keyboard_ && has_external_keyboard_);
-       ++iter) {
-    ui::InputDeviceType type = (*iter).type;
+  for (const ui::KeyboardDevice& device :
+       device_data_manager->keyboard_devices()) {
+    if (has_internal_keyboard_ && has_external_keyboard_)
+      break;
+    ui::InputDeviceType type = device.type;
     if (type == ui::InputDeviceType::INPUT_DEVICE_INTERNAL)
       has_internal_keyboard_ = true;
     if (type == ui::InputDeviceType::INPUT_DEVICE_EXTERNAL)

ash/virtual_keyboard_controller_unittest.cc

@@ -185,5 +185,18 @@ TEST_F(VirtualKeyboardControllerAutoTest, SuppressedIfExternalKeyboardPresent) {
   ASSERT_FALSE(IsVirtualKeyboardSuppressed());
 }
 
+// Tests handling multiple keyboards. Catches crbug.com/430252
+TEST_F(VirtualKeyboardControllerAutoTest, HandleMultipleKeyboardsPresent) {
+  std::vector<ui::KeyboardDevice> keyboards;
+  keyboards.push_back(ui::KeyboardDevice(
+      1, ui::InputDeviceType::INPUT_DEVICE_INTERNAL, "keyboard"));
+  keyboards.push_back(ui::KeyboardDevice(
+      2, ui::InputDeviceType::INPUT_DEVICE_EXTERNAL, "keyboard"));
+  keyboards.push_back(ui::KeyboardDevice(
+      3, ui::InputDeviceType::INPUT_DEVICE_EXTERNAL, "keyboard"));
+  UpdateKeyboardDevices(keyboards);
+  ASSERT_FALSE(keyboard::IsKeyboardEnabled());
+}
+
 }  // namespace test
 }  // namespace ash